| JDK 9 has | |
| [`Map#ofEntries`](https://docs.oracle.com/javase/9/docs/api/java/util/Map.html#ofEntries-java.util.Map.Entry...-) | |
| factory which throws runtime error when provided multiple entries with the same | |
| key. | |
| For eg, the following code is erroneously adding two entries with `Foo` as key. | |
| ``` | |
| Map<String, String> map = Map.ofEntries( | |
| Map.entry("Foo", "Bar"), | |
| Map.entry("Ping", "Pong"), | |
| Map.entry("Kit", "Kat"), | |
| Map.entry("Foo", "Bar")); | |
| ``` |